Rings of Rock

On the Salisbury Plain in Wiltshire, England, stands the third megalithic site we will discuss in this book. Its most famous component is Stonehenge. But that's not all that's there. Describing Stonehenge is not difficult, but one must keep in mind that what we see today is the result of a long process of successive phases of construction and reconstruction that spans nearly a millennium.

At first, around 3000 BC, Stonehenge was just a henge, that is, a big circular ditch about 2 meters deep and 114 meters in diameter, to which corresponded a concentric ring made from the earth removed from the ditch (the fact that the ditch was normally on the inside with respect to the earth-ring of the henges excludes a priori any hypothesis of a defensive function). Within this circle was another circle of 56 holes placed at regular intervals, called Aubrey holes after their discoverer, which were perhaps used to anchor big wooden posts.

Some centuries later, wood gave way to stone. The outer ring of the complex structure was a large circle of 30 trilithons, each composed of two vertical megaliths capped by a third, strung together in an uninterrupted circle. Inside this ring were erected five enormous free-standing trilithons, disconnected from one another. The weight of the vertical stones of the inner group is more than 50 tons each, with the horizontal architraves tipping the scales at a mere 20 tons. The architraves are not, as it may appear, simply placed there but rather fixed with mortise and tenon joints, meaning that cavities were carved into the caps to accommodate corresponding protrusions on the top surfaces of the bearing stones. The big free-standing trilithons in the center are disposed so as to form a U (customarily called a horseshoe). The central geometric axis that divides the horseshoe in half corresponds to the axis of symmetry for the monument as a whole. If we project this axis outside the circle, it meets a single menhir known as the Heelstone, clearly placed there explicitly to define this alignment.

Also belonging to the complex are four megaliths traditionally called station stones, which define a rectangle inscribed within the outlying ring of

Aubrey holes. All the blocks used here are made of local sandstone, called sarsens, and come from an area near Avebury, about 30 kilometers away. These huge sarsens were carefully shaped in the parts that were to remain above ground, while the parts to be buried were crudely "flaked" with a technique similar to that used for making flint tools at the time (remember that Stonehenge is from the early Eneolithic, or Copper Age, and that the only tools available were made of stone, wood, or horn). The result of this flaking method, whether intentional or not, is that these enormous sarsens look an awful lot like macroscopic replicas of hand tools of the Neolithic Age.

Stonehenge also has a secondary perimetral circle and secondary horseshoe made of monoliths much lighter than the monstrous sarsens (3 to 4 tons each on average). There is something curious about them, however; these monoliths are of a type of dolerite known as bluestone, which is not native to the area. In fact, the nearest source is in the Preseli Hills in modern-day Wales, well over 200 kilometers distant.

Scholars have long and strongly doubted that the megalithic people were capable of organizing the transport of dozens and dozens of these stones

(each one about the size of four or five washing machines laid end to end and weighing the same as an adult elephant) along a route as long as it was full of obstacles, to the point where some even posited the preposterous idea that the bluestones were already there at Stonehenge, transported by glacial movement during the previous ice age. Since there is not a trace of even the smallest fragment of bluestone in a radius of many kilometers, this theory was wisely discarded and today it is agreed that the stones were quarried from the Preseli Hills, transported to the banks of the Bristol Channel, transferred onto pirogues, and then floated, first by sea and then up the River Avon to a point as close as possible to Stonehenge.

In that sphere of experimental archaeology that is enjoying so much success of late, one amateur group, the Menter Preseli, managed to get financing for a modern-day attempt to repeat the process of transporting a bluestone, an undertaking that was given the humble and unassuming name of Millennium Stone Project.

At first, the volunteers who hauled the stone (which weighed an absolutely reasonable 3V2 tons) breezed through the heroic enterprise as if it were a weekend outing. The only problem was that they were going so slowly that it soon became clear that the "millennium" part of the production, which

Figure 2.3: Stonehenge from inside

Figure 2.4: The huge Sarsen trilithons at Stonehenge.

would have seen them arrive triumphantly at Stonehenge on New Year's Day, 2000, was not going to happen. Forging nevertheless onward, they finally got to the hard part: transporting the megalith down Bristol Channel on a wooden pirogue. The pirogue in question, evidently displeased with the monumentality of the task assigned to it, promptly tipped the millennium stone into the drink. The water was deep enough that navy divers were called in to find it, after which it was deftly fished out by a decidedly post-megalithic-era crane. In the meantime, enthusiasm (and the remaining funds) were running out as quickly as the millennium itself. To make a long story short, the millennium stone now lies forlornly, with a little placard that cruelly reports its name, in the Carmarthenshire Botanical Garden, despite the belief of many—myself included—that it belongs back home in the Preseli Hills.

Except for a few ax-shaped engravings on some of the sarsens and maybe a couple of human profiles (which, however, could be of natural origin), Stonehenge is a completely anonymous monument. The reason why the site itself was chosen to erect a structure requiring such enormous time and effort remains unknown to us. What is certain is that the entire plain was conceived as a sacred landscape incorporating dozens of other monuments in the course of many centuries. Among them are two long cursuses. One, called the Avenue, starts in the vicinity of the Heelstone and runs northeast for 400 meters before veering off toward the River Avon. Another, at least as old as the first phase of Stonehenge, 100 meters wide and more than a

Figure 2.5: The possible paths of the Bluestones from Preseli to Stonehenge

kilometer long, connects it with a group of tumuli. Finally, about 3 kilometers east of Stonehenge there are two other henges, Durrington Walls and Woodhenge.

Durrington Walls, which today is in ruinous condition, was a big henge measuring a formidable 520 meters. The perimetral mound alone was 27 meters wide and the corresponding ditch 6 meters deep. Evidence of post holes indicates that monument was a wooden structure, with two openings at points northwest and southeast onto the banks of the Avon.

Woodhenge owes its name to the fact that it was originally an enormous construction made of wooden posts—stripped trees, basically. Discovered only in 1920 by a reconnaissance flight, it was a ring 85 meters in diameter, open at the northwestern quadrant like its lithic neighbor, Stonehenge, and encompassed six other concentric rings of which there remain only the post holes. Though not very impressive today, the complex must have been quite a sight, with posts which, judging by the diameter of the holes, must have been a good 8 meters tall and weighed at least a few tons; it was thus made of megadendrs instead of megaliths. The excavations of Woodhenge have given us little to go on: the tomb of a child and some potsherds.